Research Output
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PublicationNear-Infrared (NIR) Silver Sulfide (Ag₂S) Semiconductor Photocatalyst Film for Degradation of Methylene Blue Solution( 2023-01-01)A silver sulfide (Ag2S) semiconductor photocatalyst film has been successfully synthesized using a solution casting method. To produce the photocatalyst films, two types of Ag2S powder were used: a commercialized and synthesized powder. For the commercialized powder (CF/comAg2S), the Ag2S underwent a rarefaction process to reduce its crystallite size from 52 nm to 10 nm, followed by incorporation into microcrystalline cellulose using a solution casting method under the presence of an alkaline/urea solution. A similar process was applied to the synthesized Ag2S powder (CF/syntAg2S), resulting from the co-precipitation process of silver nitrate (AgNO3) and thiourea. The prepared photocatalyst films and their photocatalytic efficiency were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-visible spectroscopy (UV-Vis). The results showed that the incorporation of the Ag2S powder into the cellulose films could reduce the peak intensity of the oxygen-containing functional group, which indicated the formation of a composite film. The study of the crystal structure confirmed that all of the as-prepared samples featured a monoclinic acanthite Ag2S structure with space group P21/C. It was found that the degradation rate of the methylene blue dye reached 100% within 2 h under sunlight exposure when using CF/comAg2S and 98.6% for the CF/syntAg2S photocatalyst film, and only 48.1% for the bare Ag2S powder. For the non-exposure sunlight samples, the degradation rate of only 33–35% indicated the importance of the semiconductor near-infrared (NIR) Ag2S photocatalyst used.
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PublicationControlling the Layer Thickness of Zinc Oxide Photoanode and the Dye-Soaking Time for an Optimal-Efficiency Dye-Sensitized Solar Cell( 2023-01-01)Dye-sensitized solar cells (DSSCs) were developed by exploiting the photovoltaic effect to convert solar energy into electrical energy. The photoanode layer thickness significantly affects the semiconductor film’s ability to carry electronic charges, adsorb sensitizing dye molecules, and lower the recombination of photo-excited electrons injected into the semiconductor. This study investigated the dependence of the zinc oxide (ZnO) photoanode thin-film thickness and the film soaking time in N719 dye on the photocurrent–voltage characteristics. The ZnO photoanode was applied to glass using the doctor blade method. The thickness was varied by changing the scotch tape layers. The ZnO-based DSSC attained an efficiency of 2.77% with three-layered photoanodes soaked in the dye for three hours, compared to a maximum efficiency of 0.68% that was achieved with three cycles using the dip-coating method in other research. The layer thickness of the ZnO photoanode and its optimal adsorption time for the dye are important parameters that determine the efficiency of the DSSC. Therefore, this work provides important insights to further improve the performance of DSSCs.
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PublicationNear-Infrared (NIR) Silver Sulfide (Ag2S) Semiconductor Photocatalyst Film for Degradation of Methylene Blue Solution( 2023-01-01)A silver sulfide (Ag2S) semiconductor photocatalyst film has been successfully synthesized using a solution casting method. To produce the photocatalyst films, two types of Ag2S powder were used: a commercialized and synthesized powder. For the commercialized powder (CF/comAg2S), the Ag2S underwent a rarefaction process to reduce its crystallite size from 52 nm to 10 nm, followed by incorporation into microcrystalline cellulose using a solution casting method under the presence of an alkaline/urea solution. A similar process was applied to the synthesized Ag2S powder (CF/syntAg2S), resulting from the co-precipitation process of silver nitrate (AgNO3) and thiourea. The prepared photocatalyst films and their photocatalytic efficiency were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and UV-visible spectroscopy (UV-Vis). The results showed that the incorporation of the Ag2S powder into the cellulose films could reduce the peak intensity of the oxygen-containing functional group, which indicated the formation of a composite film. The study of the crystal structure confirmed that all of the as-prepared samples featured a monoclinic acanthite Ag2S structure with space group P21/C. It was found that the degradation rate of the methylene blue dye reached 100% within 2 h under sunlight exposure when using CF/comAg2S and 98.6% for the CF/syntAg2S photocatalyst film, and only 48.1% for the bare Ag2S powder. For the non-exposure sunlight samples, the degradation rate of only 33–35% indicated the importance of the semiconductor near-infrared (NIR) Ag2S photocatalyst used.
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PublicationEnhancement of Power Conversion Efficiency with Zinc Oxide as Photoanode and Cyanococcus, Punica granatum L., and Vitis vinifera as Natural Fruit Dyes for Dye-Sensitized Solar Cells( 2022-11-01)Ruthenium N719 is a well-known material used as the dye in commercial dye-sensitized solar cell (DSSC) devices. However, it poses risks to human health and the environment over time. On the other hand, titanium dioxide (TiO2) has low electron mobility and high recombination losses when used as a photoanode in this photovoltaic technology device. In addition, using Ruthenium as the dye material harms the environment and human health. As an alternative sensitizer to compensate Ruthenium on two different photoanodes (TiO2 and ZnO), we constructed DSSC devices in this study using three different natural dyes (blueberry, pomegranate, and black grape). In good agreement with the anthocyanin content in the fruits, black grape, with the highest anthocyanin content (450.3 mg/L) compared to other fruit dyes (blueberry—386.6 mg/L and pomegranate—450.3 mg/L), resulted in the highest energy conversion efficiency (3.63%) for the natural dye-based DSSC. Furthermore, this research proved that the electrical performance of natural dye sensitizer in DSSC applications with a ZnO photoanode is better than using hazardous Ru N719 dye with a TiO2 photoanode owing to the advantage of high electron mobility in ZnO.
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PublicationEnhancement of Power Conversion Efficiency with Zinc Oxide as Photoanode and Cyanococcus, Punica granatum L., and Vitis vinifera as Natural Fruit Dyes for Dye-Sensitized Solar Cells( 2022-11-01)Ruthenium N719 is a well-known material used as the dye in commercial dye-sensitized solar cell (DSSC) devices. However, it poses risks to human health and the environment over time. On the other hand, titanium dioxide (TiO2) has low electron mobility and high recombination losses when used as a photoanode in this photovoltaic technology device. In addition, using Ruthenium as the dye material harms the environment and human health. As an alternative sensitizer to compensate Ruthenium on two different photoanodes (TiO2 and ZnO), we constructed DSSC devices in this study using three different natural dyes (blueberry, pomegranate, and black grape). In good agreement with the anthocyanin content in the fruits, black grape, with the highest anthocyanin content (450.3 mg/L) compared to other fruit dyes (blueberry—386.6 mg/L and pomegranate—450.3 mg/L), resulted in the highest energy conversion efficiency (3.63%) for the natural dye-based DSSC. Furthermore, this research proved that the electrical performance of natural dye sensitizer in DSSC applications with a ZnO photoanode is better than using hazardous Ru N719 dye with a TiO2 photoanode owing to the advantage of high electron mobility in ZnO.
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